DNA sequencing can be carried out to find the contents of a DNA molecule. Sequencing of this type may be done by using a slab gel to separate DNA molecules. The gel is heated to denature the DNA molecules, and then acts like a sieve so that different molecular parts travel at different speeds.
The rate of migration of DNA molecules that are 1 kb or smaller through a gel is approximately related to a linear function of the voltage across the gel. Therefore, it may be desirable to apply a higher voltage gradient across these gels, to increase the speed of the process.
It has been found by the present inventors that the gel plus buffer combination may behave as a bulk resistive material. As larger voltages are applied across the gel, more power is dissipated due to Joule heating.
The inventors found that this heat should be removed to prevent the matrix temperature from rising to a point where melting or bubble formation occurs. These latter effects could effect or destroy the separation properties of the matrix. It has been found that energy dissipation efficiency of the matrix may be a primary limiting factor in the voltage gradient they can be applied to a gel, e.g. and acrylamide gel or more generally any separation matrix.
In addition, a temperature gradient caused by cooling which is too intense may actually effect the measurement. The present application also describes minimizing temperature gradients during the voltage application.
The present application describes a system which allows the significant heat dissipation, retaining the advantages of slab gels, but allowing heat to be dissipated therefrom.
In one embodiment, a thin support structure is used which removes energy generated by Joule heating of the gel. This is done without generating a large temperature differential across the support medium.